<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
     <title>Document</title>
</head>
<body>
    
    <div class="container">
        <div class="row">
            <div class="col-md-4" style="background: #EEE">.col-md-4</div>
            <div class="col-md-4 offset-md-4" style="background: #CCC">.col-md-4 .offset-md-4</div>
          </div>
          <div class="row">
            <div class="col-md-3 offset-md-3">.col-md-3 .offset-md-3</div>
            <div class="col-md-3 offset-md-3">.col-md-3 .offset-md-3</div>
          </div>
          <div class="row">
            <div class="col-md-6 offset-md-3">.col-md-6 .offset-md-3</div>
          </div>
    </div>
</body>
</html>